The Construction of Highly Efficient and Stable Pt-Perovskite Sites by Hydrogen Plasma for Toluene Oxidation

Abstract

Perovskite is a promising material for catalytic oxidation of volatile organic compounds (VOCs) because of its special tunable properties as well as high stability, but commonly suffers from relatively low catalytic activity due to limited numbers of active sites caused by high synthesis temperature required. To improve its reactivity, a promising strategy is to construct highly dispersed noble metal sites with the perovskite. However, generating highly active metallic sites while exhibiting good thermal stability remains a formidable challenge. Here we demonstrate the construction of highly efficient and robust platinum-perovskite sites on La0.8Sr0.2MnO3-δ (Pt/LSMO) for toluene oxidation to achieve almost triple-fold increase in toluene conversion over the conventional samples while exhibiting a good stability. The key to the construction of Pt-perovskite sites is treating the Pt species on LSMO with hydrogen (H2) plasma at low temperatures, which leads to the formation of ultrasmall Pt metallic nanoparticles (~1.3 nm) and high concentration of oxygen vacancy (Ov). These features facilitate the generation of a large number of highly active and stable Pt0-Mn3+-Ov sites on Pt/LSMO, which activate toluene and oxygen species. This investigation demonstrates a promising approach of plasma technique to design and construct high-performing noble-based perovskite catalysts for toluene oxidation.

Keywords: Plasma treatment, Pt nanocatalyst, perovskite, VOCs oxidation